A Michigan grandmother has been charged with murder after allegedly shooting her 17-year-old grandson multiple times in her West Bloomfield home as the boy pleaded for help.

The grandmother, Sandra Layne, 74, was charged with open murder, which carries a life sentence, as well as carrying a firearm in commission of a felony.

Jonathan Hoffman, 17, had been staying with his grandmother in her condo in the Maple West Villas Complex. On Friday at 5:30 p.m., Hoffman called police to report that he had been shot by Layne. Neighbors had called in minutes earlier alerting police of shots.

Dispatchers listened as the teenager screamed and told police that he had been shot multiple times. According to Lt. Tim Diamond of the West Bloomfield Police Department, officers who had just arrived on the scene heard shots ringing out as Hoffman pleaded on the phone with dispatchers.

Hoffman was taken to Botsford Hospital and was pronounced dead 30 minutes later. A preliminary medical report found that there were two bullets in Hoffman's body and that he had eight entry or exit wounds. A full autopsy report will not be released for weeks.

Layne had come to the door still bearing the .40 caliber semi-automatic gun, and told police that she had just shot her grandson. She was immediately arrested. Only the two of them were in the condo at the time of the shooting.

Diamond says that this is this first case that their department has seen like this.

"The circumstances are shocking and tragic. We've had husbands and wives killing each other but this is the first we've heard of a grandmother shooting a grandson," Diamond told ABC News.

He says that Layne had no prior record and the department has seen no indication why she would do something like this.

One of Layne's lawyers, Mitchell Ribitwer, however, says that perhaps there is more to the situation. Hoffman, a senior at Farmington Central High School, an alternative school, had been staying there with his grandmother and grandfather since July. His parents, who are divorced, and his 15-year-old sister live in Arizona.

Hoffman been busted in March for drug possession and Ribitwer says that Layne had called police after Hoffman had behaved erratically, threatening her and using profane slurs.

"It might be a justifiable homicide, a person has the right to defend themselves," Ribitwer said.

He said that Layne, at her arraignment on Monday, was "withdrawn, depressed, and confused" and "traumatized" by the event.

Michael Hoffman, the father of the boy, who was 5 feet 5 inches tall and weighed 110 pounds, said that nothing could justify Layne murdering her own grandson.

"As far as I'm concerned, we lost our son, and anything that happens to her won't change that," he told the Detroit News.

No trial date has been set. Layne is being held in prison without bond.